Coincidentally, Team Vuo had been playing around with some spline code, so we plan to clean that up and include it in Vuo 1.2.5. It uses the Tension/Continuity/Bias parameterization developed by Doris H. U. Kochanek and Richard H. Bartels in their 1984 SIGGRAPH paper.

I'm wanting to make something that can run through data and animate a curve. Imagine morphing through this set of energy demand data curves from one coloured line to the next over time. Smoothing the data series points using linear interpolation and then having a Spline function smooth out the curve itself would be a cool node for me to use and have an excuse to learn Vuo!

I probably could do this faster in After Effect once off but I want something more generalised and procedural that I can throw all kinds of data at and switch settings and layers on the fly.

Yep, the spline node could do that. You would input the data series points as control points, and the spline node would output a larger list of points that you could feed into Make Line Strip Mesh to draw a pretty curve.

Smoothing the data series points using linear interpolation

Actually that would be the hard part, because Vuo doesn't yet have a node to smooth/interpolate from one data series to another. (Feature request: Smooth List Values.) I guess you could work out a solution using Build List or Process List — see Magneson's PetriDish composition.

If I learnt Vuo node authoring then maybe I could make this node myself based on the Javascript Smooth patch for QC that was a workaround for when you couldn't put a Smooth patch inside an Iterator macro (or it was too slow when you could). Good holiday project. I'm endeavouring to use the Kineme Spline patch to make this in QC ATM as it's an environment I know and i can render to Quartz Crystal for a nice rendering. But a Vuo app would be nice.